About this world
Kepler-458 c is a Neptune-like planet orbiting KIC 9663113, a yellow-white F-type star 5.2 thousand light-years from Earth. It is about 4.2 times the size of Earth. It completes an orbit every 20.7 days at 0.17 AU from its star, closer than Mercury is to the Sun.
Its equilibrium temperature is about 798 K (525 °C): far too hot for liquid water on its surface. At its size it almost certainly keeps a deep envelope of hydrogen and helium.
It was discovered in 2016 by transit with Kepler. A planet crosses its star and dims it by a tiny, periodic fraction. KIC 9663113 has 2 known planets; the others are KIC 9663113 b.